The proposed study is an investigation of how middle aged and older people cope with the onset of one of several chronic diseases: hypertension, diabetes mellitus, chronic lymphocytic leukemia, lymphoma, multiple myeloma, and rheumatoid arthritis. Strategies of coping with illness to be considered include: health behaviors aimed at mastering the demands of illness, and intrapychic and affiliative behaviors aimed at mastering the distress of being ill. Basic research objectives include: 1) a description of overt and intrapsychic activities employed in the process of coping, 2) a determination of those coping strategies which are effective in maintaining the individual's sense of well-being and sustaining a positive self-concept and appropriate level of physical functioning, and 3) a delineation of the interaction of personality and situational factors which determines what coping strategies are used by the middle aged or older person. Data will be obtained through face-to-face interviews with newly diagnosed patients and with patients who have known of their diagnosis for at least one year. Follow-up interviews, conducted six months after the initial interview, provide the data for assessing changes in health status, coping strategies and psycho-social adjustment. Research questions will be addressed using univariate and multivariate statistical analyses.